1. Field of Invention
This invention relates to the field of contamination removal, specifically the removal and separation of Volatile Organic Compounds ("VOCs") and Non-VOCs from the ground, or ground water, or both.
2. Description of Prior Art
VOCs and Non-VOCs are placed in the ground from time to time. Once these compounds enter the ground, they disperse downward through the vadose(unsaturated) zone to the water table. While these compounds are falling to the water table, they leave a residual trail of the compound behind in the vadose zone. When the compounds reach the water table they may form a layer on top or dissolve slightly into the water, or both.
The removal of VOCs and Non-VOCs has been accomplished in many ways. A common method is to dig the compounds up with the associated contaminated soil and ship off-site to a treatment facility. The compound can be "waterflooded" to the surface by filling the vadose zone with water and leaching the compound to the surface. U.S. Pat. No. 4,323,122 (Kropik, April, 1982) proposed the use of a vacuum applied to a bore hole open to the water table with the assumption that the lighter than water contaminant (gasoline) would vaporize and be drawn off at and around the water table level. This process may be useful for vapor recovery, but does not address the recovery and separation of contamination from the water.
U.S. Pat. No. 5,050,676 (Hess, et al, September, 1991) proposes the application of sufficient vacuum, by means of a liquid ring vacuum pump, to a borehole or well coupled with air inlet wells to cause the liquid and gaseous phases to come to the surface in a common stream for further separation and treatment. This method requires additional inlet wells, a source of water to secure vacuum with the liquid ring vacuum pump, an expensive pump for effluent discharge, and liquid particulate filtration. In a continuation or improvement of the U.S. Pat. No. 5,050,676, U.S. Pat. No. 5,076,360 (Morrow, December, 1991) proposes a priming method when the borehole or well will not extract liquids. In accordance with the present invention, which exploits total fluid recovery and separation of VOC and Non-VOC contaminants, a simple "dry" vacuum device applies vacuum to a conventional well.